Effect Of Curcumin Combined With Docetaxel On Apoptosis Of Human Prostate Cancer Cell Line PC-3

Objective： To investigate the effects of curcumin(CCM) combined withdocetaxel(DOC) on proliferation and apoptosis of human prostate cancercell line PC-3and its mechanisms. Methods：The growth inhibition ratioswere measured by MTT assay, apoptosis rates were examined by flowcytometry(FCM), the expressions of Bcl-2/Bax mRNA and Bcl-2/Baxprotein was detected using RT-PCR and Western blot， respectively. Theexpressions of caspase-8protein were detected using SPimmunohistochemistry. Results: CCM or DOC could effectively inhibitthe proliferation of the PC-3cells as a concentration-dependent manner, theinhibitory rate of combination treatment with CCM and DOC wassignificantly higher than that of CCM or DOC repectively (P <0.05), and itwas further confirmed by flow cytometry that the inductive effect on cellapoptosis became more obvious than that curcumin or docetaxel alone,when CCM combined with DOC (P<0.05). RT-PCR and Western blotshowed that CCM or DOC obviously down-regulated the expression rate of Bcl-2mRNA and protein, the expression rates of the combinations withCCM and DOC were obviously decreased compared with that of CCM orDOC repectively. CCM or DOC obviously up-regulated the expression rateof Bax mRNA and protein, the expression rates of the combinations wereobviously increased compared with that of curcumin or docetaxel alone. SPimmunohistochemistry showed that the expression rate of caspase-8protein was obviously up regulated, and the expression rates of thecombinations were obviously increased compared with that of curcumin ordocetaxel alone. Conclusion: CCM combined with DOC have obvioussynergistic effects in inhibiting the proliferation of PC-3cells andenhancing the effects on inducing apoptosis.The potential mechanismsenhancing the effects on inducing apoptosis effect may be that CCMcombined with DOC decrease the expression rate of Bcl-2and increasesthe expression rate of Bax.